The present invention in general relates to an improved measuring apparatus, and in particular to an improved electronic apparatus for the lineal measurement of materials, such as cloth transported across a cloth cutting table drawn off a cloth roll to a selected or measured length and cut.
Conventional industrial and commercial practices frequently involve the bulk manufacture of a basic material (such as fabrics or papers) in a continuous or stranded length. Such materials may be initially stored or transported to a plant in a rolled or similar condition and subsequently used in various manners in the production of finished goods. Literally hundreds of different types of materials are typically made in continuous or strand form (i.e., in bulk) and wound onto a package or roll (often tailored to the material or to machinery for handling the wound materials). For example, there are numerous types of cloth or fabric (both manmade and natural, and combinations thereof), all types of paper products and strip materials, such as wire, lace, chains, threads, and numerous other materials.
In many instances, such bulk materials are retained and transported in a rolled condition on a package or other rotatable member from which they may be subsequently unwound as desired for processing. If it is desired to withdraw measured segments from the rolls, then a technical problem is presented of accurately determining a lineal measurement of a strand or continuous type material stored in a rolled condition.
It should be apparent that in any industrial or commercial situation where a measurement is being made, the accuracy of such measurement is generally important, and may be particularly important in certain instances. For example, where a given length of continuous material is required for inclusion in a product or the like, even a slightly shortened piece (due to an inaccurate measurement) can render the entire piece of material useless, and perhaps can even create other waste in manufacture of the product if the inaccuracy is detected too late. If several shorter continuous segments have to be pieced, the resulting product might be regarded as inferior grade, i.e., a "second." Also, a piecing operation can reduce efficiency and is likely to be labor intensive, all of which adds to cost which is even more highly undesirable when only an inferior grade product is being obtained. On the other hand, uncontrolled use of excessive amounts of material (i.e., a segment longer than is required) directly generates materials waste and higher cost in production.
With certain types of materials such as wallpapers, fabrics, and the like which have repeating patterns thereon, a mismeasured cut (such as based on an inaccurate reading) can result in pattern mismatches, which can again create tremendous amounts of waste in unusable segments of material or substandard final products, even though only relatively small amounts of material might be involved in the actual inaccurate cut. For example, one tenth of a yard of material may be relatively inexpensive, but if a miscut of such degree creates an unacceptable mismatch of patterns, a relatively expensive product such as a men's or women's business suit can be rendered substandard, which could greatly reduce the market value thereof.
In addition to the foregoing concerns, it is a frequent occurrence that cloth or other fabrics on rolls or bolts are manually handled during their further processing. Such fact naturally introduces another potential factor for errors during handling, particularly in the case of measurements. In many instances, an operator is involved with drawing off cloth segments from a roll of cloth, measuring such segments, and cutting such segments. Typically such is done with an arrangement referred to as a cloth cutting table, which has a relatively clear upper surface or top work area across which the cloth or other fabric is drawn to be measured and cut. Such would be a very slow, tedious, and probably inaccurate process if the operator had to measure the segment with a yardstick or other ruler. This is particularly true for longer segments (for example, five or ten yards) which would require multiple yardstick positions for measuring and which cannot all be stretched out on the cloth cutting table at a given instant such as for ease of measurement with a tape measure. Clearly, it would not be desirable for an operator to let production materials such as cloth or paper goods which are subject to staining, etc., be spilled onto or otherwise regularly come into contact with a commercial production floor. Such a floor may often, even under the best of circumstances, have small amounts of grease or other contaminants on a concrete or similar flooring, since the large materials handling equipment, such as lifts, dollies, forklifts, etc., must be maintained with grease and the like.
More specifically, the Measuregraph Company of St. Louis, Mo., has marketed a device known as the Model 261 Counter for use on cloth cutting tables. Such product bears U.S. Pat. No. 3,131,479, by Somogye, Jr., which relates to a lineal measuring apparatus. As illustrated and discussed therein in detail, such device has opposing rolls, one of which operates as a contact roll while the other operates as a measuring roll.
Somogye, Jr., '479 discloses two basic embodiments of a mechanical lineal measuring apparatus. The embodiment of FIGS. 1 through 10 involves a lower contact roller 3 and an upper measuring roller 13, which is supported on a pair of arms or linkages 7 and 8. A contact pressure adjusting mechanism 9 makes use of a compensating spring 107 to adjust the amount of force between rolls 13 and 3.
Those of ordinary skill in the art will readily appreciate that such a compensating spring 107 is subject to tension and compression variations over time, as well as fatigue effects, which can give rise to the need to make frequent adjustments to the contact pressure. Additionally, it is inherent to the Somogye device that a controlled amount of force be used to bring together rollers 3 and 13, with excessive compression or forces thereto being a problem in one direction, while lack of adequate pressure can contribute to a roller bouncing problem which Somogye is trying to overcome. Somogye attempts to use the force of compensating spring 107 to counterbalance the effects of gravitational forces. See column 5, lines 16 through 22. However, adjusting knob 103 is intended to be used by an operator to manually select proper contact pressure for the firmness of material to be measured whenever it is desired to measure a length of material. See column 6, lines 25 through 28.
In the alternate embodiment (FIGS. 11 through 17) of Somogye, an anti-spin device is used with a lower measuring roll and an upper contact roll. The lower measuring roll is connected through a ratchet and pawl arrangement to a clutch drive, which is interconnected with a shaft 137 in turn connected through a chain drive 133 to a mechanical counter. A lifter mechanism 219 is provided to remove pressure from the relatively soft peripheries of the contact rollers 215 during their nonuse, since gravity and pressure thereagainst will result in deformation. See column 8, lines 61 through 69. A projecting finger 193 is used to physically disengage the ratchet mechanism whenever materials are feed between the rolls so as to be measured.
In practice, experience shows that it is not unusual for the contact and measuring rollers of the foregoing embodiment to be left in an engaged condition, so that a flattened or worn area develops on the contact rollers, which is highly undesirable and can lead to misoperation of the measuring device (i.e.. inaccurate measurements).
Furthermore, frequent readjusting may be necessary to properly counterbalance and adjust the configuration of the parallel-motion mechanisms, and other numerous mechanical features by which a requisite contact pressure is sought to be obtained. As is readily apparent to those of ordinary skill in the art, the necessity of such adjustments provide further opportunities for the introduction of error during measurement operations, and provide another area requiring operator training and experience, which may be lacking in some instances. Maintenance to proper working order of such highly mechanical constructions is another drawback.
Still further, it is known that production demands (and inertial friction) will require an operator to pull cloth between the opposing rolls with some force. In such event, the measuring roll would tend to continue some rotation even after a trailing edge of the cloth departs from between the rolls. The mechanical arrangement of using a ratchet grip to prevent rotation of the measuring shaft during potential subsequent rotation of the measuring wheel due to built up momentum thereof, clearly has inherent limitations when it comes to accuracy of measurements.